Orange Hawkweed
Orange Hawkweed Leaf

Asteraceae or Sunflower Family
Hieracium aurantiacum

IDENTIFICATION:
Growth Habit:
Perennial herb, ranges from 1-3 feet in height. The entire plant contains a milky juice.
Leaves: Basal rosette consists of narrow, spatula-shaped, hairy leaves four to six inches long and darker green on the upper than the lower surface. Bristly hairs appear on the leaves.
Stems: Usually leafless flowering stems, occasionally one to three small leaves present. Bristly hairs present on the stem.
Flowers: Five to 30 flower heads form a compact, umbelliform inflorescence on the terminal stems. Flower heads have red-orange petals with notched tips. Flower by mid-June and produce seeds by August.
Roots: Shallow, fibrous, and creeping. One flowering plant can produce 4 to 12 leafy stolons that can reach a length of 4 to 12 inches. Vigorous stolon growth quickly expands the colony, forming dense patches that can have as many as 3,200 plants per square yard.
Seeds: Viable up to 7 years.
Reproduction: By seeds, rhizomes, stolons, and adventitious root buds. Reproduces asexually.
Habitat: Moist pastures, forest meadows, abandoned fields, clearcuts, and roadsides.

MANAGEMENT OPTIONS:

Handpulling: Handpulling will only be effective on small infestations when rosettes and the majority of the stolons are removed repeatedly and consistently throughout the growing season.
Mowing: Mowing is not an effective method of control for hawkweed because it grows below the level of most mower blades. Mowing flowerheads only may reduce seed production but also stimulates vegetative spread.
Biological Control: N/A
Grazing: Grazing hawkweed has a similar effect as mowing. While flowers may be grazed, the majority of the plant grows too low to the ground to be utilized as forage, therefore stimulating vegetative spread. Grazing may also have a negative effect on desirable species, which will also increase the competitiveness of hawkweed. 
Herbicides: The following herbicides have been labelled for the control of the orange hawkweed. Always consult product labels and read them carefully to ensure correct species/land management usage and chemical application.

Trade Name: Active Ingredients: Rate:   Efficacy:   Comments: 
 Forefront R&P aminopyralid + 2,4-D  2-2.5 pts/acre  most effective if used from bolting stage to bud stage  Can be applied to waters edge; 
cannot be used in landscaped areas and current or future vegetable gardens, 
mulch or manure from treated areas should not be applied to vegetable gardens or composted for vegetable gardens 
 Milestone aminopyralid  4-6 oz/acre  most effective if used from bolting stage to bud stage   Can be applied to waters edge; 
cannot be used in landscaped areas and current or future vegetable gardens, 
mulch or manure from treated areas should not be applied to vegetable gardens or composted for vegetable gardens   
 Transline clopyralid  1.5 pts/acre  most effective if used from bolting stage to bud stage   Do not apply to shallow groundwater areas 


 

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